Question: Why do some cats become more ''wild'' as they age, being more violent and aggresive towards other animals and people?

Kevin Mahon answered on 14 Jun 2012:

It all depends on the cat themselves, obviously this isn;t something that typically happens, pet cats tend to get more mellow with age as a rule of thumb – exploring less, hunting less and not going as far from home when wandering.

Cats that get more aggressive with age can be down to a variety of factors including poor access to resources or inability to express natural behaviours. Cats that have their routines changed after several years can get quite stressed and aggressive as a result – a cat that had 10 years of unrestricted access to the outdoors in the countryside will adapt poorly to being made move into a small indoor aparemnet for example.